Heretofore, a blood treatment filter device is known which removes specific components (typically leukocytes) in blood. The blood treatment filter device is a device which filters blood through a filter filled with nonwoven fabric and the like to remove specific components in the blood. Since the operation of the blood treatment filter device of the configuration described above is simple and the removal ratio of specific components in blood is high, the blood treatment filter device has been widely used heretofore.
Most of such blood treatment filter devices are configured by a wound body in which a filter sheet is cylindrically wound and in which specific components in blood are captured by the filter in a process in which the blood flows from the outer peripheral surface to the inner peripheral surface of the wound body. Such a blood treatment filter device has had a problem that, when the filter sheet is clogged on the outer peripheral surface side of the wound body, the blood becomes difficult to flow to the inside of the clogged portion, so that the pressure required for flowing the blood through the wound body becomes high.
To address such a problem, a configuration has been devised in which, in a blood treatment filter device having a cylindrical-shaped filter material in which a blood treatment filter layer and a spacer layer, through which blood more easily flows as compared with the blood treatment filter layer, are wound in a laminated state, an end portion of the spacer layer is exposed to the outer peripheral surface of the cylindrical-shaped filter material. According to this configuration, even when the blood treatment filter layer on the outermost periphery of the cylindrical-shaped filter material is clogged, blood flows into the inner peripheral surface side in a spiral shape along the spacer layer from the end portion of the spacer layer exposed to the outer peripheral surface, whereby the blood can reach the blood treatment filter layer on the inner peripheral surface side, so that specific components of the blood can be captured in the filter layer on the inner peripheral surface side (Patent Literature 1).
The blood treatment filter device needs to be subjected to priming treatment of introducing a priming liquid (for example, physiological saline) to remove foreign substance and air (hereinafter referred to as “air and the like”) in a circuit before use. For example, Patent Literature 2 describes an example of priming treatment including a first process of charging a priming liquid into a retransfusion-side circuit from the outside and, simultaneously therewith, discharging an initial charged-liquid from the retransfusion-side circuit of a blood treatment unit and a second process of introducing the priming liquid to the blood treatment unit through the retransfusion-side circuit.